Add extended tooltips

mods/ITEMS/mcl_monster_eggs/init.lua

@@ -23,6 +23,7 @@ local register_block = function(subname, description, tiles, is_ground_content)
 		is_ground_content = false,
 		sounds = mcl_sounds.node_sound_stone_defaults(),
 		after_dig_node = spawn_silverfish,
+		_tt_help = S("Hides a silverfish"),
 		_doc_items_longdesc = S("An infested block is a block from which a silverfish will pop out when it is broken. It looks identical to its normal counterpart."),
 		_mcl_hardness = 0,
 		_mcl_blast_resistance = 3.75,